A Proinflammatory Invariant Natural Killer T Cells Phenotypic State Associates with Human Graft-Versus-Host Disease Onset and Response

• Published in: BLOOD 2018-11, Vol.132 (Supplement 1), p.2111-2111
• Main Authors: Erkers, Tom, Xei, Bryan, Kenyon, Laura, Rieck, Mary, Basina, Marina, Jensen, Kent, Strober, Samuel, Negrin, Robert S., Maecker, Holden T., Meyer, Everett H
• Format: Article
• Language: English
• Subjects: Medicin och hälsovetenskap
• ISSN: 0006-4971; 1528-0020
• DOI: 10.1182/blood-2018-99-120358

Human invariant natural killer T cells (iNKT) are a rare population of lymphocytes that bridges innate and adaptive immune functions. iNKT cells have different potent effector functions and subsets, but this heterogeneity is mostly understood by a superimposed framework of classic T cell markers. This may help explain contradictory studies of iNKT cells in diseases for which they are thought to play a pathogenic role. In this study, we present data suggesting new markers to understand human iNKT cell heterogeneity and function, as well as monitoring this in the clinical context of allogeneic stem cell transplantation (ASCT) and graft-versus-host disease (GVHD). In both preclinical murine models and in correlative clinical studies, iNKT cells are associated with less GVHD and better immune reconstitution following ASCT. We performed bulk whole transcriptome sequencing on iNKT cells from patients at day +30 after ASCT, some who developed and some who did not develop GVHD. Gene expression signatures of the iNKT cells from each individual are grouped based on a transcriptome library of reference cell types (CIBERSORT). Using this approach, we distinguished patients who will develop GVHD as predominately having an activated cytotoxic cell gene signature, whereas patients without GVHD had a CD4+ T cell gene signature within purified peripheral blood iNKT cells. Using two different high throughput single-cell RNA sequencing (sc-seq) platforms to determine differential gene expression on the single cell level, we first examined the gene expression signatures of primary human iNKT cells from healthy donors. Activation with CD3/28 microbeads of primary iNKT cells promoted two main differential transcriptional profiles in iNKT cells. One profile resembles conventional CD4+ T cells and associated Th2 cytokine profile (IL2, IL4), whereas the other profile has genes associated with cytotoxicity and inflammation (TNF, IFNG, GZMB). Confirmation by flow cytometry showed that while CD8 surface expression did not well differentiate the pro-inflammatory and cytotoxic subsets, but both CD94 and KLRG1 better associate with Th1 and cytotoxic responses. CD94+ iNKT are restricted to CD4- cells and KLRG1 expressed in both CD4+ and CD4- populations. By comparison, the analysis of sc-seq of normal healthy subjects and post-transplant patients with and without GVHD resulted in the identification of three major iNKT populations. The population most associated with GVHD showed expressio